Kevin
When I bought my new Denon x4300w AVR I wanted to make sure it stayed cool and calm. I don't know that I ever had heat issues with my old Denon, but, I wanted to make sure I didn't have them with the new one. So, I bought an Aircom Infinity S9. Hands down a great product. Dead quiet. Runs when it needs to, doesn't when it doesn't.
The S10 is a front exhaust unit. The S9 is a top exhaust. That didn't make any difference to me then, and wouldn't now either. The T series have more stuff on the front panel. I don't look at that as a positive. It means a more distracting faceplate when you're just looking to listen to music without a bunch of light blaring at you in a subdued room. On the S9, you can disable the front panel bright circle of light. I did that.
The S9 disappears on top of my AVR. I know its there, but, its so unobtrusive it literally just disappears.
Its a great purchase even if its just for peace of mind. Two thumbs up from here.